Entanglement-assisted Delayed-Choice Experiment

Here we report a experimental realization of that assisted by polarization entanglement of photon pairs. Nearly perfect polarization correlation between two photons can be employed to this delayed-choice experiment and then enable the space-like separation of the "choice-maker" (which is the polarization projection of one photon done by a Pockel Cell controlled by Quantum Random Number Generator) and single photon pulses. On one hand when we detected the single photon pulse in closed interferometer, high visiblity interference pattern show the signature of wave nature of it. On the other hand when we detected the single photon pulse in opened interferometer, no interference is shown at all which shows the particle nature of it.